1. Field of the Invention
This invention relates generally to filling systems for high pressure air tanks, and is more particularly concerned with means for filling an air tank for a breathing apparatus without removing the breathing apparatus from the user.
1. Discussion of the Prior Art
In the conventional self contained breathing apparatus (SCBA), the apparatus includes at least one air tank. When the air tank is to be filled, the user must take off the SCBA and remove the tank from the SCBA. The tank is then filled, the tank reconnected to the SCBA, and the user again puts on the SCBA. This process requires a good bit of time and trouble.
When an SCBA is used for pleasure, as in underwater exploration, one might easily tolerate the time required to fill a tank, or to exchange tanks; but, in emergency situations as with a fire fighter, the time to fill a tank or to exchange tanks is time the fire fighter may need to save someone from a fire, or to assist in extinguishing a fire.
While it may appear at first blush to be an obvious thing to provide a separate fill valve for an air tank on an SCBA, it must be realized that safety considerations prevent the use of an extension hose that could be damaged and quickly empty the air tank. The existing hoses of an SCBA include means for preventing rapid discharge of air, the mouthpiece being connected through a dual pressure regulator, and the gauge being connected through a small orifice for severely restricting air flow. Thus, neither of these standard items is readily adaptable to tank filling.